This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2000-311533, filed Oct. 12, 2000; and No. 2000-311534, filed Oct. 12, 2000, the entire contents of both of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a small antenna used for a mobile telephone, a mobile information terminal, and a terminal device of a wireless LAN (local area network) etc.
2. Description of the Related Art
Conventionally, an antenna in which the antenna conductor is formed on a surface of a dielectric substrate in a meander shape (see Jpn. Pat. Appln. KOKAI Publication No. 10-229304) and the antenna conductor is formed in a helical shape in the dielectric substrate (see Jpn. Pat. Appln. KOKAI Publication No. 10-98322) are well-known as a small antenna which is used for a mobile telephone etc.
However, when mounting the antenna on a circuit board, it is necessary to mount the antenna directed to a certain direction to show an enough performance as an antenna in a conventional small antenna. Therefore, a conventional small antenna has a small freedom of selection of the mounting directions. Therefore, it is difficult to correspond to the plurality of models with one kind of antenna. Therefore, it takes time of the design, and the cost is raised. In addition, there is a disadvantage that an area necessary for mounting the antenna is enlarged since the conventional antenna should be away from the edge of the ground plate to some degree.
In the antenna with a meander or helical antenna conductor, by providing the capacity addition part whose width of the conductor is wide to the tip of the antenna conductor (end portion being opposite side of the feeder part), since the length of the antenna conductor can be shortened, it is known that the antenna is miniaturized.
However, the further miniaturization of an antenna is required in a cellular phone etc.
An object of the present invention is to provide a small antenna, which has a high degree of freedom when mounting the antenna on a circuit board and is more miniaturized.
A small antenna according to the present invention is characterized by comprising: a first meander part formed in such a manner that a meander conductor travels to a first direction and having a first end and a second end; and a second meander part formed in such a manner that a meander conductor travels to a second direction different from the first direction and having a first end connected with the second end of the first meander part and a second end.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter,